Latch tripping mechanism



R. A. SHIELDS LATCH TRIPPING MECHANISM 2 Sheets-Sheet l Oct. 25, 1955Filed July 12, 1951 Oct. 25, Y1955 R. A. sHlELns LATCH TRIPPINGMECHANISM 2 Sheets-Sheet 2 Filed July 12 1951 United States Patent ilce2,721,667 Patented Oct. -25, 1955 LATCH'TRIPIING MECHANISM yRobert A.Shields, Bloomsburg, Pa., assignor -to ACF lndustriesJncorporated, vacorporationv of 'N ew .lersey VApplication July 12, 19s1,seria1'N0.z2s6,42s

9.Claims. 4,(Cl. 214-58) This invention relates to latchtrippingvmechanisms in general, .and ein, particular to latch trippingmechanisms for-use with/automatically operated `drop bottom door .minecars. VDrop V.bottom -mine cars have in .the n past been -.tripped vbytrackside mechanism exacting .lan up- 1ward.pressure eitherfron an arm,projecting to the side `of -the `car 4or `upon mechanism mounted beneathvthe car. With either Vfof these mechanisms .it is necessary-thatthelocomotive and .other `types oftcars-ride over the'trippingmechanism or=the trippingmechanism must .be moved to-one'side. `In-caseswhere-the locomotive rides 'over the 'mechanism excessive wear 'takesplace .due `to .the necessary `heavy .upward pressures lwhich isincreased -due Vto .the collapsed position tof `the Ytripper. -It is.-an object therefore lof .the present `invent-ion toprovideYa-tripping.mechanism in which the vupward pressure.decreasesbetween the upright'and collapsedy position.

A further objectfof the vinventionis ythe l.provision of f atripping-.mechanism whichis resiliently.heldinaraised kpositionand tripsthe car latches by downward pressure.

A still further objectofthe invention is the provision .of.a latch,trippingmechanism having 1the :parts so larrangedrthat the nerectingleverage decreases yat a ifaster rate than Vthe spring 4tensionincreases during fcollapse of the tripping mechanism.

A yet further object of the1invention is theprovision `of alatchtripping `mechanism whichvmay be 'used to trip various'types of latches.

These androther objects of -the invention will beiappar- .ent .topersons skilled in :the art ffrom a study :of `the Yfollowingdescription 'and accompanying drawings, in

which Fig. `1 -is aside elevation Vof Ythe improved itripping mechanism;

Fig. 2yis-aplan viewfof the mechanism;

4-l-Tig. `Itis'an'end viewiof the mechanism showing the relation toacar; and

Fig. 44 is anrelevati'onal View showingthe =relation ofthe:trippingmechanismsto' the .cars and dumping pit.

Referring'nowfto` the .drawings in detailit` will be lseen that thetripping mechanism indicated generally at A is adaptedto Abe locatedalongsidethe track and at the approach side'of thertbinlB. The carsCtravelling along the track are equipped with drop-bottom doors .D and alatch mechanism connected to a tripping .arm As clearly shown in Fig.'4, the tripping mechanismtis permanently mounted on thetrestle orvpermanent structure with :the arms in position to engage .the trippingarm E, thereby unlatching the doors and permitting them to open whentheyfreach the dumpingbin B.

The tripping mechanism, asrclearlyshown, is yformed -.vithfabase portionhaving a baseplate 2 provided with holes 4 by means of which the basemay be bolted or otherwise fastened to the trackside structure. Spacedplates 6 project upwardly from the ends of base plate 2 and are suitablygusseted to the base, as at 8. They are also stil-'tened by a crosstie10, welded or otherwise secured to plate 6 above pivot pins 12. Thepivot pins continuations ofthe flanges.

.offarms 22and 24. rllangesare connected,.as at.36,byplates welded tothe 12 extend Vthrough the upstanding plate 6, and are longitudinally.movable in slots 14 .formed in the plate v6. Inwardly .of .the pivotpins and .between plate 6 a pair of lugs 16 are welded, vand at leastone of these is threaded to receive anadjusting .screw 1S. The remotelends -of the adjusting screws are adapted Vto bear upon rollers 20carried on pivotpins 12, and .adapted to roll .along .base plate 2,thereby relieving any wear on the pivot pins.

A pair-of lever. arms 22 Yand.24 of generally inverted.channelcrosssection are provide'd, and havethe lower ends oftheirllanges .pierced to engage the pivot pins lf2 and .have aportion-of the web cutaway to clear lrollers .20. The upper .ends of theanges of arm 22 flanges and preventing any spreadingor squeezing tend-.ency that might be imparted vby bolts 34. ln order Vto trip the carlatches, va 'tripping projection 40 is welded .or ,otherwiseisecured Vtothe-lever arm 22 adjacent its .upper.end, and this-projection is adaptedto'engage over the. outwardly projecting vlatch control arm rE.

As Ashown `in =Fig. vl, 4the arms .22 and .24 lmake an angle` of`approximately 221/2 degreesrwith-respect to the base or`with respectto-the line of pull of lspring 32.

-When .the deviceiscollapsed beneath a locomotive end Vinto the dottedline position, -these angles are approximately f6 degrees. 4By.arranging the lever arms and springrconnections, as shown, it isobvious-that the tension in spring 32 will -increase vduring collapse ofthe ftripper as fthe cosine yof the angle. It is also obvious thatVduring collapse `the -leverage through which the springcan act willdecrease as the sine of `the angle. Itis 4well `known Vthat `as an angleapproaches zero, the sine of the angle also approaches zero at amuch`faster rate .than-the cosineapproaches unity. Withzparts connected-asshown, the erectingpressure'will decrease and be materially lessin'thecollapsed :position thanin `the upper or-raised position. lWiththeparts-as shown, this ldecrease is approximately one-third, -therebyvgiving an extremely soft faction, preventing 'damage to ,the underparts'of the .locomotive or other structures passing over the trippingdevice.

From the preceding description it is obvious that by adjusting thefstopscrews 18 the height of tripping pro- -jection 40.mayfbe`nicelykadjusted and'held'to a definite relation with respect vto 'the base.IWhena locomotive moves :toward the dumping `bin, it'will strike arm 24,

thereby forcing pivot pin 26 downwardly and causing the pin 12 of arm-22'to moveoutwardly in its-slot 14. As

Vsoon as thisjpinstrikesthe end of its slot, then the pin 12 of farm.24willfmoveoutwardly inits slot, permitting the mechanism tol assume the.dotted lineposition. IIn the movement ,from the raised to thelowereldposition,the

v spring 32-will have itstension increasedslightly,fbutat a much .lessrate Vthan the y'leverage armihas been decreased. As soon asthe-locomotivehastpassed'overfthe .trippen `,the ,springwill'pullthefarms tortheir :raised or full line position with therollers 20 bearing against adjusting screws 18. As soon as the latchtripping arm E comes in contact with projection 40, it will be urgeddownwardly, since the projection is held in its raised position by thespring and by the engagement of rollers 20 with adjusting screws 18.

In certain cases it may be desirable to pass cars without tripping, andthis may be accomplished either by pulling the tripper down by mechanism(not shown), or it may be locked in a down position by inserting a pin42 through holes in one pair of side plates 6 and above the web of anarm such as 22. In certain instances where cars of the type shown inFig. 3 operate in train with the conventional cars having arms extendingto the side of the car and tripped by upward pressure, then the pin 42may be again inserted through the holes in plate 6 and through alignedholes in the depending ilanges of arm 22. Thus this same pin may lockthe tripping dcvice in either the down or the raised position. Incertain cases it will, of course, be undesirable to lock the device inthe raised position, but the conventional cars may be tripped byincreasing the tension of spring 32 by adjusting its connection with thearms, thereby giving sufficient tension to trip the conventional latcharm, which in this case will ride up along the arm 24.

While the invention has been described more or less in detail withspecic reference to the drawings, it will be obvious that variousmodifications and rearrangements of parts may be made without departingfrom the scope of the claims dening my invention.

What is claimed is:

l. In a car door latch tripping device, a base member adapted to bemounted adjacent the trackway, a pair of levers pivotally mounted on thebase member for upward and downward swinging movement, said pivotalmount including a sliding connection between the levers and base, meanscarried by said levers to yieldingly hold said levers in a raisedposition, means to limit the upward swinging and sliding movement ofsaid levers, and means connected to one of said levers and adapted toengage a car carried latch operator part and exert downward pressurethereon to move the operator part downwardly during movement of the carpast said tripping device.

2. The structure of claim 1 characterized in that said last-named meanscomprises a projection extending laterally from one side of said onelever and sloping downwardly longitudinally of the trackway and in thedirection of car travel during tripping.

3. The structure of claim l characterized in that said second-namedmeans comprises stop members adjustably carried by said base andengaging the levers whereby the uppermost and innermost position of saidlevers may be controlled.

4. In a car door latch tripping device, a base member adapted to bemounted adjacent the trackway, a pair of levers pivoted together attheir upper ends and diverging downwardly, each lever at its lower endhaving a pivotal and translational mounting on said base member forupward and downward swinging and sliding movement, resilient meansconnected only to and acting on said levers to normally hold the same inupward position, means connected to said base and controlling thetranslational movement of the lower ends of the levers, and meansconnected to one of said levers and adapted to engage a car carriedlatch operator part and exert downward pressure thereon during movementof the car past the tripping device.

5. In a car door latch tripping device, a base member adapted to bemounted adjacent the trackway, a pair of levers pivoted together attheir upper ends and diverge ing downwardly to spaced apart pivotal andtranslational mountings at their lower ends on said base member forupward and downward swing and sliding movement, said mountings limitingthe upward movement of said levers, resilient means carried by andacting on said levers to normally hold the same in upward position, andmeans connected to one of said levers and sloping downwardlylongitudinally of the trackway in the direction of car travel duringtripping and adapted to engage a car carried latch operator part 'andexert downward pressure thereon.

6. In a car door latch tripping device, a base member adapted to bemounted adjacent a trackway and including upwardly extending sideplates, horizontal slots formed in said side plates, a pair of levershaving their lower ends pivotally and slidably mounted in said slots andtheir upper ends pivoted together to form an inverted V, resilient meanscarried by said levers and nor mally holding the upper ends of saidlevers in upwardly' spaced relationship to said base, and meansconnected to one of said levers and adapted when the levers are inraised position to engage a car carried latch operator part and exertdownward pressure thereon to move the part downwardly during movement ofthe car past the tripping device.

7. In a car door latch tripping device, a base member adapted to bemounted adjacent a trackway and including upwardly extending sideplates, horizontal slots formed in said side plates, a pair of levershaving their lower ends pivotally and slidably mounted in said slots andtheir upper ends pivoted together, resilient means connected to saidlevers and together therewith forming an A frame, and a projectionconnected to one of said levers adjacent the apex of the A and adaptedto engage a car carried latch operator part and exert downward pressurethereon during movement of the car past the tripping device.

8. In a car door latch tripping device, a base member adapted to bemounted adjacent the trackway, tripping means adapted to engage a carcarried latch operator part and exert downward pressure thereon duringmovement of the car past the tripping device, and means connected tosaid tripping means and to said base and normally holding said trippingmeans in a raised position to contact the latch operator part butmovable to a lowered position incapable of contacting the latch operatorpart, said means including resilient means connected to the trippingmeans and having the leverage varied during movement of the trippingmeans so as to exert greater raising effort on the tripping means whenin raised position than in lowered position.

9. In a car door latch tripping device movable between a raised andlowered position, a base member adapted to be mounted adjacent atrackway and including upwardly extending side plates, horizontal slotsformed in said side plates, a pair of levers having their lower endspivotally and slidably mounted in said slots and their upper endspivoted together, resilient means connected to said levers intermediatetheir common pivotal connection and their lower ends, said commonpivotal connection moving downwardly toward said resilient means duringdownward swinging movement of said levers whereby the eitective leverageis varied so that the resilient means will exert greater raising efforton the tripping means when in raised position than when in loweredposition.

References Cited in the tile of this patent UNITED STATES PATENTS893,053 Clarke et al. July 14, 1908 905,080 Jones Nov. 24, 19081,388,388 Swank Aug. 23, l92l 2,225,463 Rose Dec. 17, 1940 2,522,197Sanford Sept. l2, 1950 FOREIGN PATENTS 626,459 Great Britain July 15,1949 962,200 France June 2, 1950

